Blood could generate body repair kit
A small company in London, UK, claims to have developed a technique that overturns scientific dogma and could revolutionise medicine. It says it can turn ordinary blood into cells capable of regenerating damaged or diseased tissues. This could transform the treatment of everything from heart disease to Parkinson's.
If the company, TriStem, really can do what it says, there would be no need to bother with conventional stem cells, currently one of the hottest fields of research. But its astounding claims have been met with bemusement and disbelief by mainstream researchers.
TriStem has been claiming for years that it can take a half a litre of anyone's blood, extract the white blood cells and make them revert to a "stem-cell-like" state within hours. The cells can be turned into beating heart cells for mending hearts, nerve cells for restoring brains and so on.
The company has now finally provided proof that at least some of its claims might be true. In collaboration with independent researchers in the US, the company has used its technique to turn white blood cells into the blood-generating stem cells found in bone marrow.
When injected into mice, these cells migrated to the bone marrow and generated nearly all the different types of human blood cells, the team will report in the January edition of Current Medical Research and Opinion (vol 20, p 87), a peer-reviewed journal.
"I would be extremely sceptical of these findings and would need more proof," says stem cell expert Evan Snyder of the Burnham Institute in La Jolla, California, whose response is typical of many scientists New Scientist contacted.
"I was extremely sceptical," says team member Tim McCaffrey, a cardiovascular researcher at George Washington University in Washington DC, who was asked to evaluate TriStem's claims. "They did it in front of my eyes with my own blood," he says. "It's stunning."
Even if replacing bone marrow is all TriStem's method can achieve, it is still significant. Tens of thousands of people need bone marrow transplants each year. In some cases, doctors already extract stem cells from the blood instead of transplanting bone marrow itself. A donor is given growth factors that make their marrow stem cells proliferate and spill over into the blood, but the procedure takes several days.
TriStem's method might make it possible to obtain vast numbers of blood stem cells in a fraction of the time. "What's radical is the speed and ease with which it works," McCaffrey says.
But the company claims it can do much, much more. Ilham Abuljadayel, the founder of TriStem, says that by adapting standard culturing methods she has managed to turn white blood cells into heart, nerve, bone, cartilage, smooth muscle, liver and pancreatic cells.
TriStem has not yet published results proving all these claims. Since the company has worked only with human cells, it cannot perform what is regarded as the "gold standard" test of stem cells' versatility: inserting them into an embryo to show they can form all the different tissues. But if TriStem's method really can produce a wide range of cells, its potential is huge.
For starters, it would avoid the ethical issues associated with embryonic stem cells, the most versatile kind of stem cell. TriStem's method would also make it easy to treat individuals with their own cells, avoiding any problems with immune rejection. The only way to obtain ESCs that match a patient's own tissues would be therapeutic cloning, yet to be achieved with human cells.
The adult stem cells found in various tissues in the body could also solve both these problems. But there is still much debate about their versatility, and even if some are capable of forming just about any cell type, they are scarce. Extracting and multiplying them is difficult and time-consuming.
In addition, TriStem's claims challenge the scientific dogma that specialised cells cannot revert back to an unspecialised state or be converted from one type to another. Other groups also claim that they can "transdifferentiate" cells (New Scientist print edition, 12 October 2002). But none can do so as swiftly and easily as TriStem.
Its "miracle" hinges on an antibody manufactured by DakoCytomation of Denmark that is normally used to detect abnormal brain cells. In the early 1990s, while working as a consultant immunologist, Abuljadayel tried to use the antibody to kill leukaemia cells. Instead of dying, the cells altered form and flourished.
Abuljadayel says the antibody binds to a receptor on the cell surface. But how the antibody triggers "retrodifferentiation", if indeed it does, remains to be established. To avoid arguments about whether the cells produced are genuine stem cells, she calls them "stem-cell-like cells".
Abuljadayel applied for a patent on retrodifferentiation in 1994, and in 1999 founded TriStem with the help of her husband, Ghazi Dhoot, then an investment banker. The company has long struggled to convince mainstream scientists that its system works.
Like TriStem, McCaffrey encourages sceptics to try the procedure themselves before condemning it. "I don't think there's voodoo involved, but until a number of people do it, other scientists have every right to be cautious," he says.
For many researchers, alarm bells ring loudest over the failure of TriStem to get such groundbreaking results published in a leading journal. They also ask why Abuljadayel has had no permanent academic position.
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